From his seminal discovery that microfilariae of Wuchereria bancrofti develop in certain mosquitoes, Sir Patrick Manson evolved a hypothesis about filarial transmission: that people became infected by drinking water into which infective larvae had escaped from dead or dying mosquitoes. This unconfirmed concept lasted from 1878 to 1900 when new evidence indicated that transmission occurred via the mosquitoes' bite. Manson's concept was revived when experiments in 1972 in my laboratory showed that Brugia pahangi, a filaria closely related to W. bancrofti, is transmissible orally to birds, and furthermore, that infective larvae spontaneously escape from dead or dying mosquitoes placed on water. Stimulated by these findings, I have re-examined the publications of Manson and his contemporaries to trace the origins, development, and abandonment of Manson's concept. I have also assembled from the more modern literature numerous reports (i) that such larvae can survive in various natural fluids, based on this research, and (ii) that such larvae can survive in various natural fluids. Based on this research, I have prepared a manuscript (60-plus pages in first draft) setting out and analyzing the historical and scientific antecedents of the experiments that led to the indirect confirmation of Manson's hypothesis. Of necessity, this manuscript borrows from the writings of Sir Patrick Manson-Bahr, Manson's son-in-law and principal biographer. Manson-Bahr's relevant papers and books, while essential source-materials, are riddled with errors on conflicts of fact and interpretation. More important, however, is that Manson-Bahr based much of his writings on the unpublished diary kept by Manson and still conserved in London where it is available for study. To complete the draft manuscript, I must be able to clarify Maason-Bahr's allusions to the diary, and to learn what more it contains that he overlooked or ignored concerning filial transmission. Assuming approval of this application, the relevant features of Manson's diary will be incorporated into the manuscript and submitted for publication in an appropriate scholarly journal. The proposed research has important implications biologically, historically, and perhaps epidemiologically, for one can no longer escape the possibility that two patterns of filarial transmission exist - one via the skin, and the second via the mouth.